L-amino acid oxidase

Abstract

PCT No. PCT/DK94/00168 Sec. 371 Date Nov. 2, 1995 Sec. 102(e) Date Nov. 2, 1995 PCT Filed Apr. 27, 1994 PCT Pub. No. WO94/25574 PCT Pub. Date Nov. 10, 1994An L-amino oxidase isolated from Trichoderma harzianumi is disclosed. The enzyme exhibits activity on L-arginine, L-lysine, L-methionine, L-asparagine, L phenylalanine, and L-leucine. The pH optimium of the enzyme is alkaline.

We claim: 
     
       1. An L-amino acid oxidase E.C. 1.4.3.2 isolated from Trichodenna harzianum A611, CBS 223.93 and characterized by having the following properties: (A) pH optimum in the range of from pH 8.5 to 9.5 determined after incubation for 20 minutes at 20° C. in the presence of L-arginine;   (B) pH stability of 80% or more, relative to initial activity, at pH 9.5 determined after incubation for 1 hour at 40° C. in the absence of substrate; and   (C) activity towards L-arginine, L-lysine, L-methionine, L-asparagine, L-phenylalanine, and L-leucine.   
     
     
       2. A process for the preparation of an L-amino acid oxidase according to claim 1, which process comprises cultivation of an L-amino acid oxidase producing strain of Trichoderma harzianum AC11, CBS 223.93, in a suitable nutrient medium, containing carbon and nitrogen sources and inorganic salts, followed by recovery of the desired enzyme. 
     
     
       3. A process for in situ generation of hydrogen peroxide, comprising the step of adding the L-amino acid oxidase of claim 1 to a solution containing a substrate for said oxidase. 
     
     
       4. A detergent additive comprising an L-amino acid oxidase according to claim 1, wherein the detergent additive is in a form selected from the group consisting of a granulate, a non-dusting granulate, a liquid, a stabilized liquid, a slurry, or a protected enzyme. 
     
     
       5. A detergent additive according to claim 4, which further comprises a substrate for the oxidase. 
     
     
       6. A detergent composition comprising an L-amino acid oxidase according to claim 1, and comprising a substrate for the oxidase. 
     
     
       7. A detergent composition according to claim 6, which further comprises one or more other enzymes selected from the group consisting of proteases, lipases, amylases, cellulases, peroxidases, and other oxidases. 
     
     
       8. A detergent composition according to claim 7, in which the peroxidase is derived from Coprinus, or from Bacillus, or in which the peroxidase is derived from plants. 
     
     
       9. A process for inhibiting the transfer of a textile dye from a dyed fabric to another fabric when said fabrics are washed and/or rinsed together in a wash liquor, the process comprising adding an L-amino acid oxidase according to claim 1 to the wash liquor in which said fabrics are washed and/or rinsed. 
     
     
       10. A detergent composition according to claim 8, wherein the peroxidase is derived from one of Coprinus cinereus, Coprinus macrorhizus, Bacillus pumilus, or horseradish.